Frequency-responsive device.



B. FRANKENFIELD.

FREQUENCY BESPONSIVE DEVICE.

APPLIGATIOH FILED MABJZ, 1910.

1,029,007, Patnted June 11, 1912.

UNITED STATES PATENT OFFICE. BUDD rnauxnnrmnn, or nos ANGELES, clihfroanm, assrenoa To Arms-- CHALMEBS COMPANY, A CORPORATION or NEW JERSEY.

FREQUENCY-BESPONSIVE DEVICE.

Patented June 11, 1912.

, My invention relates to frequency-respon- I sive devices.

1 It is often desirable to have some means which isresponsive to the frequency in an alternating current circuitmeans which will operate in one direction when the frequency is below a predetermined normal value and in the other when the frequency is above such normal value.

It is the object of my invention'to provide such means. In attaining this object there are provided two relatively movablewindings, which, for convenience may be called armature and field windings, and

these windings are supplied from the circuit to the frequency in which it is desired that the device be responsive. The fluxes due to thecurrents in the two windings are caused to be I displaced from each other both in time and space'by angles which at normal frequency are such that no torque is produced. When the frequency rises above or .falls below normal, the time-displa'cement between the armature and field fluxes is varied, preferably by the same means which produces such time-displacement, and in consequence a torque is developed and relative movement between the armature and field windings produced in one direction or the other according as the time-displacement has been increased or decreased.

The various novel features of my invention will be apparent from the descriptionand drawings, andwill be particularly form of my frequency-responsive device;-

pointed out in the claims.

Figure 1 shows diagrammatically one Fig. 2 shows a somewhat modified form of my frequency-responsive device arranged to control the supply of steam to a turbine driving a generator which supplies the circuit to the frequencylin which the device is responsive. v

In the arrangement shown in Fig. 1,111

alternatingcurrent circuit 10.11 supplies a field winding 12 and an armature 13, preferthe circuit of the armature l3 is placed a condenser 15 and an inductance coil 16, the latter being preferably adjustable'as by means of the movable core 17. Here the armature is of the commutator type, the magnetic poles of the armature being maintained normally fixed in space, save for reversals, by means of the adj ustable brushes 18.

The current in the field winding 12, and consequently the field flux, are substantially in timequadrature with thevoltage on the mains 10-11. The inductance of thecoil 16 is so adjusted that the circuitincluding such coil, the condenser 15, and the armature 13 is tuned for normal frequency, so that the armature current and flux are substantially in phase with the voltage on the circuit 1011 when the frequency is normal. The field and armature fluxes are thus in timequadrature. By reason of the arrangement of the brushes 18, they are also in space-quadrature. Consequently, while the frequency in the circuit 10'11 remains at its normal value, there is no torque developed tending to. cause relative motion between the field member 12 and the armature 13. If the frequency in the circuit 1011 rises above or falls below such normal value, the currentin the armature circuit becomes either lagging or leading, and the armature flux gets out of time-quadrature with the field flux. Butas the, armature flux remains in space-quadrature with the field flux, there is a tendency for the armature to-move relatively to the field member in one direction or the other according as the armature current is lagging or leading. If the armature is free to turn, the resultant rotation of the armature may be used to 0p erate a governor or a regulator of any desired type. is limited, it may be used to control relay circuits to obtain any desired results; or the armature may be mounted to operate against a spring or springs 19 so that the extent of movement of the armature is a function of the phase-displacement between the armature flux and the frequency in the circuit 1011. In this latter case the movement of the armature is a function of the departure from normal of the frequency in the circuit 10-11, and visual indication of the frequencymay be obtained by mounting a If the motion of the armature i frequency responsive device arranged the voltage of the mains 10 and 11. The in current, but if desired an inductance C01 2 pointer 20 on the shaft of the armature 13 so that it will swing over a suitable scale 21. Exact tuning of the armature circuit is not necessary, as an lack of time-quadrature between the fiel and armature fluxes may be balanced by shifting the brushes 18, it being only the fluxes so related at normal frequency that no torque is developed.

In Fig. 2 is shown 'amodification of :qy 0 control the admission of steam to a turbine. Here the frequency-responsive device, as in the arrangement shown in Fig. 1, consists of the field member 12' and the armature 13, the circuits of both being controlled by the switch 14. A condenser 22 is placed in circuit with the field member 12, and is preferably so prop'ortioned that at normal frequency thecondensive reactance and the inductive reactance 'of the' field circuit just balance, thus making this circuit .a tuned circuit. i hus the field flux in this arrangement is $11 stantially in phase with the voltage across the mains 10 and 11 of the three phase circuit -9-10-11. The current in the armature 13 is made to lag 90 behind ductive reactance of the armature itself will often be sufficient to produce this lagging which is preferably adjustable, may be placed in the armature circuit to insure quadrature.v As in the arrangement shown in Fig. 1, the field and armature fluxes are th'usin time-quadrature when the frequency in the circuit 910.-11 is normal; they are maintained in space-quadrature at all times by the brushes 18. The time-displacement between the two fluxes may be adjusted by means of the movable'core of the inductance coil 23, while the space-displacement between such fluxes may be regulated. by shifting the brushes. Any inaccuracy in the ad justment of either of these displacements may be compensated for by adjusting the other so that the angles of time and space displacement between the two fluxes are such that no torque is developed. The armature '13 is connected in any desired manner to the valve 24 through which steam is admitted to a turbine..25. driving the three phase generator 26 which supplies the circult 9 1011. When the frequency in this circuit rises above normal, the time-displacement between the field and armature fluxes of. the frequency-responsive device becomes less' than 90F and the tothe turbine '25; When the requency in V armature 13rotates to close the valve 24 to diminish the sup ly of steam this circuit falls below normal, the time-displacement between the field and armature uxes of the frequency-res onsive device becomes greater than 90 an the armature necessary. to havethe spacei displacement and the time-displacementof proper value 13 rotates in the opposite direction to open the valve 24 to increase thesupply of steam to the turbine '25. In either case the movement of' the armature 13 andvalve 24 ceases as soon as the' f-requency in the circuit.9- 10-11 is restored to normal value.

Whatever the angle of time-dis lacement between the armature and field uxes may be and'such time displacement'may be anything desired, the angle of space-dis lacement between the two fluxes is ma e of relative to that of time-dis-v lacement for normal frequency by connectmg the armature winding to the outside circuit at the proper points. This connection of the armature windingb need not be through a commutator and rushes as 'is illustrated in Figs. 1 and 2, for if the armature .has only a small movement the connection of the circuit to the, armature may be permanent. When the sum of the time and space displacements of the armature and field fluxes becomes such that the no-torque value no longer exists, as is the case whenever there is ither an increase in the inductive reactance because of an increase in frequency or an increase in the condensive reactance because of a decrease in frequency,

the armature tends to move relatively to the field in one direction or the other.

In the foregoing description the terms armature winding and field winding have been 'used for convenience. But the two windings may be precisely alike if desired, and either or both may be mounted broad aspect of my invention, that the two windings be relatively movable and be supplied from the same circuit, that the timeisplacement between the two fluxes developed vary when the frequency varies, and that the sum of the time and space displacements of the two fluxes be such for normal frequency that there is no torque developed between the two fluxes. Consequently, in actual construction the absence of torque may be obtained whemthe two angles of time and space displacement are not supplementary. The term same circuit as used above and in the claims is intended to'cover alternating current circuits of all kinds, whether single phase or polyphase.

Many modifications may be made in the precise arrangements shown and described, and all such which do not depart from the spirit and scope of my invention I aim to cover in the following claims.

What I claim as new is:

. 1. In a frequency-responsive device, a

field member having a single winding arranged to'be connected to a circuit, a relatively movable armature having a single winding arranged to be connected to the same circuit and to produce a flux interacting upon and displaced in space from that for movement. It is only necessary, in a produced by the field winding, and means associated with said windings for causing the time-displacement between the two fluxes to be such at normal frequency that no torque is produced between the armature and the field member, and for varying the time-displacement between the armature and fieldfiuxes to produce such a torque upon a change in the frequency in the circuit.

2. In a frequency-responsive device, a field winding arranged to be connected to a circuit, a relatively movable armature having a commutator and brushes and arranged to be connected to the same "circuit, the brushes being so located on the commutator that'the fluxes produced by the currents in the armature and field windings are displaced in space, and means associated with said windings for causing said fluxes to be displaced in time by an angle which is dependent upon the frequency in the circuit to which the windings are connected'and which at normal frequency is such that no torque is produced between the armature and field fluxes. I

3. In a frequency-responsive device, a field winding arranged to "be-connected to a circuit, a relatively movable armature having a commutator and brushes and arranged to be connected to the same circuit, the brushes being so located that the armature and field fluxes are substantially in spacequadrature, and means for causing the armature and field'fiuxes to be in time-quadrature upon normal frequency in the circuit so that no torque is produced between the armature and field, and for varying the timedisplacement between the two fluxes upon a change in frequency so that a torque is produced.

4. In a frequency-responsive device, a field winding arranged to be connected to a circuit, a relatively movable armature having a commutator and brushes and arranged to be connected to-the same circuit, the brushes being so located on the commu tator that the armature and field fluxes are substantially in space-quadrature, and a the torque produced between them when they are connected to the same circuit to be inopposite directions according as the frequency in said c'ircuit'is above or below a predetermined value.

Milwaukee, Wis., Feb. 24, 1910.

In testimony whereofI aflix my signature,

in the presenceof two witnesses. BUDD FRANKENFI-ELD.

Witnesses:

C. E. FISH, J. HANNA. 

